Kaposi's sarcoma is the most common cancer in persons with the acquired immunodeficiency syndrome (AIDS) worldwide, and is the most prevalent cancer in all persons living in Zimbabwe. The occurrence of KS in persons with, and without AIDS has been linked to infection with the recently discovered human herpesvirus 8 (HHV-8; also called Kaposi's sarcoma-associated virus or KSHV). Available data strongly suggest that HHV-8 is the causative agent of Kaposi's sarcoma and that coinfection with human immunodeficiency virus type 1 (HIV-1) and HHV8 greatly increases the risk of developing Kaposi's sarcoma. Thus, the present epidemic of Kaposi's sarcoma in Zimbabwe is likely the result of a high risk of concomitant infection with both HHV8 and HIV-1 in Zimbabweans. To date, the prevalence of HHV8 in Zimbabweans has not been defined and the relationship between HHV8 replication, HIV-1 related immunodeficiency and Kaposi's sarcoma pathogenesis is unknown. Even though Kaposi's sarcoma is epidemic in Zimbabwe, Zimbabwean investigators have limited experience with the techniques used to diagnose and monitor HHV8 infection and detailed studies on HHV8 epidemiology and pathogenesis in Zimbabwe have not been conducted. The purpose of the present proposal is to develop a strong collaboration between American and Zimbabwean investigators for studies on HHV8 infection and Kaposi's sarcoma. These studies will define the prevalence of HHV8 infection in Zimbabwe and to determine the relationship between HHV8 gene expression and Kaposi's sarcoma disease status in Zimbabweans with Kaposi's sarcoma. In addition to providing important information on the epidemiology and pathogenesis of HHV8 infection, it is expected that these initial studies will provide the basis for future investigations on the role of HHV8 in Kaposi's sarcoma.